Compressor



W. RUDOLPH COMPRESSOR 3 Sl'eeS-Sheet l Filed Jan. 27, 1928 iin'.

ATTORNEYS' Feb. 23, 1932. W, H- RUDOLPH 1,846,360 i COMPRESSOR 'l Filed Jan. 27. 1928 l T5 Sheets-Sheet 2 /9 15 L A TTD/e Feb. 23, 1932. w. H. RuDoLPH cou'PREsson Filed Jan.` 27, 1928 S'Sheets-Sheet 3 /NVENTo/a Patented Feb. 23, 1932 UNITED STATES PATENToFFlcE WALTER H. RUDOLPH, 0F NEW YORK, N. Y. i

COMPRESSOR y Application med January 27, i928. serial N5. 24.9.7913.-

io metrically disposed about a common axis of rotation, thereby to` secure a perfectly balanced vibrationless device which will give a substantially uniform fluid delivery, free from surging or impulses and which conse- 15 quently will notrequire the use of a storage,

or pressure equaliaing, tank.

A. further object is to provide a compressor in which there are no valves to stick, click or leali, no connecting rods, no belts or drivu ing chains, or no gears to hum or rattle.

Another object is to provide a compressor which will be adjustable to secure outputs of various maximum pressures.

A further object is to provide a device of the character to which this invention relates that will be self-cooling, self-oiling, dustprooi', rustproof and leakproof.

Another object is to construct a compressor capable of being directly connected to high au speed motors, engines, or other power sources Without requiring the use of speed reduction gears or similar devices.

A further object is to provide a compressor oit marked simplicity of construction, capable of being manufactured and sold at a relatively low cost, while at the same time being ot such sturdy construction that the maintenance cost thereof will be reduced to a mini` `there is an extensive radiating surface and therefore high thermal efficiency, will appear more fully from the following more detailed description and by reference to the accom# panying drawings forming a part hereof, wherein Fig. 1 is a central longitudinal section taken on the line 1-1 of Fig; `2, partly in elevation and partly broken away,o a compressor constructed in accordance withthe principles of my invention; Fig.2is a section `on the line 2*2 of Fig. 1; Fig. 3 is a .section on the line 3?) of Fig. 1; Fig. 4 is asection on `the line fir-1.1. of Fig. 3;' Fig. 5 is a plan view of the valve which governs the entrance and exit of the Huid being pumped; Fig. 6 is a side elevation of the valve shown in Fig. 5; Fig. 7 is a section on the` line 7--7 of Fig. 5; Fig. 8 is a sectional detail ot the coupling for connecting the compressor shaft to a driving element such as an electric motor, this figure being a vertical section taken on substantially the same lineas the section of Fig. l but showing the parts which comprise the coupling in a partially separated condition in order to show more clearly in the construction of such parts; Fig. 9 is asection on the line 9-f9 of Fig. 8; Fig. 10 is a side elevation of the end of a cylinder and piston, this view being taken substantially on the line 10--10 of Fig. 2; Fig.` 11 is a section taken on the line 114-11 of Fig. 5 and showing in additionto the valve of Fig. 5 a portion of the spindle which fits over said valve, and Fig. 12 is a detail plan taken on the line 12--12 of Fig. 1l.

In order that the moredetailed `description presently to be given will be better understood, the construction and operation of the compressor will first be brieiydescribed. It consists of a cylinderblocl mounted for rotation Within a casing about acent'ral axis. This block comprises a plurality of cylinders extending radially from said axis and in each of which is `slidably mounteda compressor piston. The cylinder block is rotated preferably at a high speed by any suitable means, such for example, as an electricmotor preferably oonnected directly to the cylinder blockV or a part intevral'therewith. The inner end of each cylin er is provided with a porter aperture which is adapted to communicate Cil MMI

during the rotation of the cylinder block with suitably arranged intake kand delivery ports of a valve member held `against rotation by suitable securing devices interposed between it and the outer casing and said valve member is located at the center of the casing, so that as thecylinder block is rotated, each cylinder lv ;/ill be placed alternately in cornmunication s with said intake and delivery ports. The reciprocation of the pistons is brought about by the eifect'of thecentrifugal force produced as a result of the rotation and by the action of a circular cam race, arranged eccentrica-Hy to the axis of rotationof the cylinder block, the centrifugal force causing the pistons to move VVoutwardly andperform a suction stroke While the cam race engages the outer ends of the pistons, orany suitable nonfriction member carried thereby, to periodically urge the pistons inwardly to perform their compression strokes.

.As shown most clearlyin Fig. 1 of the drawings, a satisfactory constructional ex ample of the invention comprises an outer easing consisting of a lower casing member 10 and uppercasing member 11. These mem bers are preferably constructed of aluminium'A in order to reduce the weight of the compresser to a minimum Vand also to obtain the advantageof the high heat conductivityy of this metal and thereby secure a maximum cooling of the device. The upper and lovver casing members 10 and 11 are connected together, adjacent to their peripheries, by anyk suitable means, suchv asthe bolts 12, and define a fluid tight oil chamber 1,3. Y The lower casing memtber 10 is provided With a pair of radially extending conduitsrlt, 15, which in the particular example illustrated, extend substantially at right angles to eachother and terminate at their outer ends at the pcriphery of the casing. The conduit-14 is the delivery conduit and the conduit v15 is the suction conduit. At their inner ends the conduits 14, 15 communicate respectively With the vertically extending conduits 16, 17 provided in a valve member 18 which seats upon a disc `19, preferably of steel, secured to the casing member as by headedscreivs 19a, the heads of which project upwardly into recesses 18a inthe valve member. :The top surface of said valvemember is substantially spherical iin 'configuration for a purpose to be hereinafter more fully set' forth andthe conduit 16 terminates at'itsupper end, in aV port 2O provided insaid top surface. The conduit 17 communicates with aport 21 also formed in the topVK of the valve member.

The main driving shaft or spindle 22 of thecompressor is arelatively short member having in the bottom thereof a central bore or recess 23,l the shape or configuration of which is similar to that of the valve member 18 so that said boreand said member 18 Will be in neat runningiit engagement.

'provided' with Va plurality of radially extending substantially conical bores 26 Which communicate at their inner ends through apertures or ports 26a provided in the spindle with the central bore 28 of said spindle.

There is one bore 26 ,for each cylinder 25 and each bore 26 at its outer end is of the saine Idiameter as the bore of each cylinder 25 and is in communication at said outer end Withits respective cylinder.

Mounted within each of the cylinders 25 is a piston 27, the inner end of which is partially conical in configuration as indicated by the reference character 28 to conform with the conical bore 26 and which isalso partially spherical in configuration as indicated by the reference character 29. The purpose of providing the pistonsat their inner ends with the conical and spherical portions is to eliminate dead air spaces or pockets and thereby reduce clearance space to an irreducible minimum. At the outer end thereof, each piston 27 has mounted therein a roller 30. Each roller 30 is rotatably mounted upona pin 31, one end of said pin being secured against rotation Within its respect-ive piston by means of a small pin 32. The periphery of each ofthe rollers 30 as shown is concaved for interengagement with the convex inner surface of a race 83. Obviously the rollers could be convex and the surface of the race concave or any other construction could be employed in which the rollers and race so interengage that the rotation of the pistons about their central axes is prevented. Y y

The race 33is of circular formation and is seated Within a groove preferably formed by counterboring the meeting faces of the upper and lower casing members 11 and, 10 respectivel ;l the inner surface of the race being eccentrically disposed relatively to the axis of rotation of thel cylinder block. The extent of eccentricity of the race relatively to the axis of rotation of the spindle 22 and cylinderblock is such that the stroke of the pistons Within the cylinders is substantially as shown by the relative positions of the pistons at the right and left hand sides of Fig. 1 of the drawings.

For the `uur )ose of 1 ermittin the com res.

sor to be adjusted for securing various maxi mum pressures, means are provided for varying the extent of the stroke of the pistons. This is accomplished by locating the axis of rotation eccentric relatively to the center of `13 the circular bottom of the groove in which the race 33 is seated, the bore of theboss lll1 being bored eccentric to the groove counterbore of the uppeil easing member li. The inner and outer surfaces of the race while circular are also eccentric. The amount of eccentric` ity of the centers of thorace groove and the inner and outer surfaces may be varied as desired in accordance with the requirements; the radius lines X, Y, Z shown in Fig. 2 show by way of example the principles of construction, the center of the radius X coincides with the axis of rotation, while the centers of Y and Z indicate the. relative positions of the parts shown in the drawings. It will be noted that, as shown, the centers of the radii Y and Z for the inner and outer surfaces of the race are located on a line extending perpendicular' to a diameter which passes through the centers of X and Y.. If now the race is rotated within its groove to bring the center of Z in said diameter' but between the centers of Y and X the strokes of the pistons will be reduced by an amount equal to twice the eccentricity of Ze-Y while if the race is rotated to bring the center of Z as far as possible from the center of X the strokes of the pistons are increased. Obviously any desired adjustment of the pistons strokes, within the limits just described, may be obtained by moving the race to positions within such limits. It will be apparent that a condition of no strolre of pistons may be obtained by making the eccentricity of Y, Z, equal to that of Y, X so that the center of the inner surface of the race may be brought into coincidence with the axis of rotation. Any suitable means may be provided for the convenient rotational. adjustn'ient of the race, as shown, the ra ce is provided on its outer surface with worin gear teeth 33 with which meshes a worin 33" secured to a shaft 33, said shaft being suitably journalled in the lower casing member and projecting outwardly thereof; the outer projectingr end of the shaft being provided with any well known means for rotating it. Rot-.ation of the race, when itis used a gasket to seal the meeting joints ofthe casing member, would be accomplished by first loosening the bolts l2. If however it is desired to have the race so that it can be rotated without looseningI of the bolts, a gasket proper positions of alignmenufor example when the compressor is moved f bodily while inoperative, the outer end iofeach cylinder has secured therein a small pin 35; said pin being fixed in a small apertured boss 36 projecting laterally from the outer upper endof each cylinder 24. The outer end of each pin 35 is bent downwardly across the outer face of its respective cylinder and projects into a longitudinally extending groove 37 provided in the outer wall of each piston. j It will be noted that the .pins 3l project into said grooves 37 and each projecting end ofeach pin is also provided with a groove which is in alignment with the groove 37 of the piston. From the above described construction it will be seen that should the pistons `move inwardly so as to bring the concave periphery of the rollers 30 out of contact with the race 33, the pins 35 will serve to keep the pistons in their proper positions of alignment." In the ordinary operation of the compressor, the rollers BOhowever are held bythe centrifugal force in engagement with the race 33 so that no strain is placed upon the pins.

For the purpose of connectingthe rotatable cylinder block to any suitable drivingmeans and preferably to an electric motor such as shown in the drawings, the following coupling construction is provided The upper reduced end of the spindle 22 is threaded and has engaged thereon an annular coupling lool; nut 40. Before the nut 40 is secured upon the spindle, a threaded coupling sleeve 4l is placed upon the upperm reduced end of the spindle. The sleeve 4l, as clearly shown in Figs. l and 8 of the drawings, is provided at its lower end with a flange 41la which surrounds the upper end of the spindle loosely and is adapted to engage under the lower face of the nut40 after the latter has been secured in position upon the spindle. The upper face of the spindle 22 is provided with coupling jaws 22, as shown most clearly in Fig. 8, and the coupling lock nut 40 is provided with similar jaws 40iL which are brought into alignment with the jaws 22 when the nut 40 is screwed home into position.v The upper reduced end Iof the spindle 22 `is provided with a bore 42 in which is adapted to be received the armature shaft 43 ofthe motor M. Said armature shaft has secured thereto, preferably by a press' fit, a lock jaw ring 44, the outer periphery of which is threaded to be engaged by the inner threaded upper end of the coupling sleeve 4l. At its lower end the coupling jaw ring 44 is provided with coupling jaws 441 adapted to engage in the recesses provided between the jaws 22 and 40 of the spindle Q9. and nut 4() respectively.

The partition wall ll of the casing meinber 1l is' provided at the center thereof with a boss 1lb. Seated within thisboss is a bushing 45 preferably of steel or other suitable g partition wall 11n.

material, having good wearing qualities and cup-shaped packing cup 47 is a -coiled-com pression spring 48 which serves to exert through the ball bearing a predetermined pressure for holding the inner spherical surface of the bore 23 of spindle 22 in engage ment with the upper spherical surface of the valve member 18. Coniined between the packing cup 47 and a bearing cap 49 is a acking gasket or washer 50 constructed of elt or other suitable material. At its outer edge the cap 49 is provided with a depending flange 49a, the inner surface of which is provided with screw threads for engagement with cooperating screw threads cut in the upper end of the bushing 45. It will be noted I. that the packing members 47, 49 and 50 form,

in effect a` stuiiing box which prevents gas leakage from the compartment 13. When the cap 49 is screwed down tight, the bushing 45 is clamped rigidly to the boss 11b by pressure exerted on the lower surface` of the boss 11? by the flange 45a of bushing 45 and on the upper surface 'of boss l1b by the lower surface of flange 49a. A cooling fan 5l is suitably secured to th armature shaft 43 for the purpose of causing a continuous vcurrent of cooling air to be drawn across the top surface of the partition wall 11a, the upper casing member 11 above the partition wall 11a beingv provided with a plurality of air admission openin s 52 spaced about the periphery 4of the vertical wall of said casing and establishingcommunication between the outside air and the compartment defined by said casing member ll above the Immediately above the openings 52 the inner vertical wall of the casing member 11 is provided with a proj ecting rib 53 which is grooved or recessed as indicated by the reference character 54. A dished baie plate 55 has pivotally mounted upon` the peripheral flangel 55@L thereof, a plurality of eccentric lock or latch members 56, said members beingsecured to said flange 55a by means of the headed rivets 57. Each latch member has a boss portion 56ab through which the rivets 57 pass and a handle portion 56b by means of which each latch may be turned upon its respective rivet. The rivets 57, as clearly shown in Fig. 3, are located eccentrically of the boss portion56 of the latches 56 so that when the latches are turnedupon said rivets, the eccentric throw of the boss portion 56a can be moved into and out of engagement with the annular groove 54. At its central portion the dished plate 55 has an aperture of suiicient Vdiameter to` clear the outer circumference of the boss l1b so that when the latches 56 are disengaged,

the baille plate 55 may be moved to the dotted plurality of bosses V59 arranged at spaced 'j intervals about Vthe casing memberand pro# vided with threaded apertures into which are adapted to be received the lower ends of the connecting bolts 60 which serve to clamp the motor M securely in engagement with the compressor unit.

' The manner in which the parts sofar described are assembled is substantially as follows: The rollers are placed within the outer hollow ends of the pistons 27 and the pins 3l are inserted into the central bearing bore of the rollers 30 and through the aligned apertures provided for their reception in the walls of the pistons. The pins 32 are inserted into the holes drilled for their reception in the piston wall and pins 31 after which the inner end of the pins 32 are bent upwardly to the position shown in Fig. l of the drawings, this being done by the insertion of a punch or the like into the small aperture 61 provided'in theV lower part of the piston wall. The pistons 27 are then'inserted into the assembly formedby the cylinder block and spindle 22, it being. understood that the cylinder block has been shrunk fit upon the lower enlarged endof the spindle. The pins y are then inserted into their bosses 36 and are locked in position by bending the inner ends of said'pins upwardly and the outer ends thereof downwardly, it being understood that the downwardly bent outer end of each pin will 'be ofA suiicient length to project into Vthe longitudinally extending groove 37 of its respective piston but out of contact with the bottom wall of said groove. The valve 18 having been placed in position within the lower casing member 10, the cylinder block and spindle assembly,with the pistons mounted therein, is placed in the lower casing member with the bore 23 of the spindle 22 engaged over the Vvalve 18. All of the pistons 27V are moved to their innermost 'limits of travel and the race 22 is then placed in-position within the halfgroove formed in the lower casing. The ball bearing46'is then placed over the upper reduced. end of the spindle 22 after which the coupling sleeve 41 is slipped over the spindle. The lock nut is then screwed home upon the spindle so as to bring the jaws 4()a thereof into cont-erminous relationship with the jaws 22a of the spindle. The upper casing member V11V with the bushing contained therein is then placed in position and the bolts 12 are inserted and screwed home toclamp the two casing sections together. The compression ioo spring 48, the packing cup 47, the packing washer 5() are placed in position in the order mentioned and the bearing cap 49 is screwed onto the bushing until its lower surface is tight against the up er surface of the boss 1lb. The dished bae plate 55 is placed within the upper casing member 11 in the dotted line position shown in Fig. 1. The fan 51 and coupling j aw ring 44 are secured to the armature shaft 43 of the motor Ni and the lower projecting end of the armature shaft 43 is inserted into the bore 42 ofthe spindle. When the coupling jaw ring comes into contact with the upper' end of the coupling sleeve 4l, said sleeve is rotated to cause the threads thereof to engage with the threads of the coupling jaw ring 44 and to draw said ring towards the upper end of the spindle. It will be understood that as thearmature shaft is inserted into the bore 42 and lowered into position, the jaws 44ab will be brought to a position that will insure their meshing with the jaws 22a and 40 of the spindle 22 and loch nut 40 respectively and that during the operation of screwing the coupling sleeve upon the coupling jaw` ring the armature shaft will be held against rotation. In order to guard against the formation of an air cushion between the lower end of the armature shaft 43 and the bottom of the bore 42 the spindle 22 is provided with a small hole 62 leading from the bottom of said bore 42. After the coupling sleeve 41 has been screwed home to clamp the jaws 44, 22iand 40@ in proper intermeshing relationship, the dished baille plate is then raised to its upper position and the latches 56 are rotated into en gagement with the annular groove 54 tolock the baille plate in its operative position. After this has been done the motor casing with the field `magnets secured thereto is placed upon the upper casing member 11 and the bolts 60 are inserted and screwed home to hold the motor and compressor parts in assembled condition. i

Means are provided for securing a continuous circulation of oil about and through the moving parts of the device, said oil acting not only to lubricate the bearing sur faces, but also as a cooling fluid` The compartment 13 defined by the upper and lower casing members is maintained partially filled with oil and advantage is taken of the fact that the cylinder block rotating at a high speed can be utilized as a pump for causing the oil within said compartment 13 toi be circulated to and about the frictional bear- `Communication between the conduit 64 and the compartment 13 is established through the small vertical conduit 66 which it will be noted communicates with the compartment 13 immediately adjacent to the inner peripheral wall thereof, the region adjacent to said` inner wall being, as will `be readily understood, the zone of greatest pressure due to the effect of centrifugal force upon the fluid. At its inner end the conduit `64 communicates with the space aboveithe ballbearing 46 by means of a vertically extending groove 67 formed in the inner wall of the boss 11b which leads to a peripheral oil conduit 67a formed in the ,outerwall `of said bushingand with which communicates a plurality of holes 68 drilled through the wall `of the bushing 45. The oil pumped through the conduits 66, 64, groove 67 `and holes 68 passes through the ball bearing 46 and circulates back to the compartment 13. In order to provide a free `passage for the oil from `the ballbearing back to the compartment, the upper face of the enlarged lower end of the spindle 22 is slightly turned down or faced'oif to provide a clearance space indicated by the reference character 69.

Lubrication of the `cooperating bearing surfaces ofthe spindle 22 and valve member 18 is effected by means of a conduit 7() formed in the lower wall of the lower casing member 10 and extending radially of said wall. At its outer end the conduit 70 terminates in a recess 70a; said recess is closed by a plug 71 and said recess communicates with theinterior of theI compartment `13 adjacent'to the inner face ofthe peripheral `wall through a hole 72. Oil maybe poured into compartment 13 by laying thecompressor on its side with the recess 70 turnedup, removingthe plug 71 and pouring oil into said recess, from whence `it will flow `into compartment 13 through hole 72. To drain oil from the compartment `13 the plug 71 is removed and the compressor is laid on its side with the recess 70 down; At its inner endythe conduit 70 communicates with a vertically extending oil conduit 73 provided in the valve member `18. The upper end of the conduit 73 of the valve member 18 terminates at the middleof the spherical surface formed on the upper face of said valve member, the oil being pumped underf pressure i by the centrifugal force through thehole 72 and conduits 70, 73 to lubricate the spherical `bearing surface. In order to preventithe lubricating `oil from being' forced into the cylinders 24, .acircular groove 74..is` formed in theinner spherical surface of the bore 23 of the spindle 22, said groove surrounding ythe exit end Vof the oil conduit 73 and being `located `between said exit end and the ports 265m the spindle. `One or more vertically extending grooves are formed in the inner end of the bore 23 of the spindle and extend from the circular groove `74thereof between adjacent ports of said llt spindle toa pointbelow said apertures to yconduct the oil from the groove to the cylindrical portion of the bearing surfaces between the bore of the spindle Vand the valve member 18. Lubrication ofthe contactingbearing surfacesof the pins 31 and rollers 30 is provided by the following means: Each piston 27 has -drilled therein a hole 76 which furnishes communication between the hollow interior of the piston and the longitudinally extending groove 37 with which the pinv 35V cooperates. The grooved end yof the pin 31 .which projects into the groove 37 is provided with an axial -hole 77 extending into the pin toa point between the side edges of the roller 30. Said axial hole communicates with the inner end of aradialhole'S in said pin andv the outer end of said radial hole leads into an oil groove 7 9 formed in the periphery of the pin and extending preferably longitudinally thereof.

As the pressure set up in the oil adjacent to the circumferentialbounding wall of the compartment 13 will normallyV be in excess of the gas pressure, means are provided for reducing the oil flow to the spherical surface of the valve member 18 in case there should be a tendency of the oil to be forced by such pressure past the circular groove 74 into the inner ends of the cylinders. Such means comprises a wick 8O ofany suitable compressible material placed in the conduit 70. A plate l81 movable transversely of said conduit by a screw 82 engages the wick 8O and serves to compress it. `Adjustment of the amount of pressure exerted by the plate on the wick will vary the rate of oil fiow through the conduit accordingly. The plate 81 is seated in a recess in the conduit and the recess and plate are so dimensioned that the lat- -ter forms a seal for preventing oil leakage around the screw 82. Y

The operation of the device is as follows: Assuming the parts have been assembled as I hereinbefore described and that the compart- Inent 13 has been filled with oil, rotation of the motor M will cause its armature shaft,

through the intermeshed jaw construction of the coupling members, to drive the cylinder block. Owing to the centrifugal force set up, the hollow pistons 27 will be Vurged outwardly of the cylinders 24 so that the rollers 3() carried by the outer ends of the pistons will be held into engagement with the race 33. The race 33k as hereinbefore described; while circular,is.A eccentric to the axis of rotationV of the cylinder block by an amount sufficient to cause the pistons when forced toV their innermost positions by the race to move approximately into engagement with the inner coneshaped endsof the cylinders, the pistons being forced inwardly to perform Ytheir compres- -sion stroke by the eccentricity ofthe cam race,

and said pistons being moved outwardly to perform their suction stroke preferably solely refieren by the influence of the centrifugal force.l As the spindle and cylinder :block rotates, the ports 26a in the spindle at the inner ends of the cylinders Awill be brought alternately into registry with the ports and 21. As the cylinder block rotates, the piston will be actuated by the centrifugal force due to the annular velocity'of the cylinder block and will consequently be forced outwardly thus holding the roller 30 in engagement with the race v and the co-action of the race and roller restraining `the outward travel of the piston. Just as the piston begins its outward travel the port 26a at the inner end of the cylinder is open to the port 21 and the communication between such ports is maintained open until the piston has reached the end of its outward stroke. The port 21 being connected through the conduits 17 and 15 to the outside atmosphere or to a fluid containing reservoir air or Huid is drawninto the cylinder to lill the space vacated by the receding piston. 'After the piston has reached its outermost limit of travel it is, upon further rotation of the cylinder block, forced inwardly by the pressure of the roller on the race. As will be noted by referring to Fig. 5 of the drawings, each cylinder will rotate through an angle of approximately 90C after the piston has begun its travel inwardly before the port 20 is uncovered. During this time the air or gas is being compressed and therefore as the port 20 is uncovered the fluid will-be ejected under pressure through the port 20 and conduit 16 to the discharge conduit 14.A

During the rotation of the cylinder block the oil contained in the compartment 13 is caused to be circulated in the manner hereinbefore described, the `oil for lubricating the ball bearing 45 being taken from the zone of greatest pressure through the conduits 66 and the oil for lubricatingthe 'cooperating bearing vsurface of the valve member 18 and 22 also being taken from the zone of greatest pressure and being delivered in both cases to a point relatively near the axis of rotation at which point the pressure due to centrifugal force is much lower than in the region adjacent to the periphery of the compartment 13; it will thus be seen that a continuous circulation of the oil under pressure is assured. The delivery of the oil under pressure between the spherical bearing surfaces bounded by the circular groove 7 4 results in the maintenance of a film of oil in'l this regionvunder sufficient pressure to act as a-cushion which very effectively takes up the end thrust due to Air is drawn in by the fan-51 through the openings 52 in the vertical wall of the upper casing member 11 and is caused to be deflected downwardly by the lower surface of the inclined wall of the dished baille plate thereby to sweep across the upper face of the partition wall 11b which forms the upper wall of the compartment 13. The air then passes up wardly through theaperture 58 and is driven outwardly by the fan and is deflected by the upper surface of the inclinedbalilc wall to pass upwardly through the motor about the field coils and armature and thence outwardly through openings provided in the top of the motor casing. Owing to the fact that the compartment 13 is well fille d with oil, the heat of compression is transmitted to the body of oil and through such body to the aluminum walls of the casing members which define the lower compartment. Likewise such heat as may be generated by the frictional contact of the moving parts is also absorbed by the oil and transmitted to the aluminum casing.

lt will be seen that as every moving` part of a compressor constructed in accordance with the principles of my invention moves in a perfect circle and that as every unit of mass which moves has an exact counterpart diametrically opposite on the orbit of rotation, there are no unbalanced centrifugal. forces, and that, as none of the moving parts have a rubbing velocity at, or near, the tangential velocity of the periphery of the cylinders, or iu excess of accepted safe limits, the compres sor may be actuated at a very high speed which speed high enough to maintain the piston rollers in Contact with the race under all con? ditions eiicountered in operation of the compressor solely and entirely by the centrifugal force developed. therefore be directly connected to a high speed electric motor without the employment of any speed reduction gears. llllthough the construction permits high speed operation and under certain circumstances such high speed will be preferred, it will be understood that the invention is not limited to high speed operation but that the principles of construction and operation are equally adapted for low speed rotations. In the latter case, if necessary, springs or the like may be employed to supplement the centrifugal forces for holding the piston rolle s against the race.

It will also be noted that allthe rotating surfaces of the moving parts are abundantly and efficiently lubricated by a body of oil which also functions as a cooling lluid. There a total absence of poppet valves, connect ing rods, z(rear, chains, belts and links, such as are employed in compressors as heretofore constructed andthe use of which necessarily limits the speed by reasons of sudden reversals in their directions of travel, unbalanced forces, and consequent excessive vibra,-

The coinpressor unit mav tion, inertia and excess noise and Wear at high speed.

Itwill furthermore be noted that noradial bearings are employed except those l of the prime mover. Only a single stationary valve, namely, the valve member 18, is employed, which member performs the function of twelve moving valves. The mounting of the valvemember 18 so that it Will beheld against rotation but has limited oscillation by reason of the engagement of the slots 1ba and the heads of thescrews 19a, renders the valve self-adjusting, thereby not only permitting a greater tolerance of dimensions in the machining of the parts, but, in addition, insuring against unequal wear upon the valve during operation. he spherical configuration of the upper surfaces of the valve also provides a vorv elicient safeguard against binding or seizing of the bearing surfaces of the spindle 22 and valve member even though the entire weight of the motor armature and the action of the spring i8 forces these two surfaces together with a considerable pressure. ln this, connection the provision'o'f the means for circulating` a lubricant under pressure to the upper end oi? the valve member is also important, be unse, as hereinbefore pointed out, the film of lubricant maintained between the spherical surface `forms a very ellective cushion toitalre up the ond thrust. Although the upper surface of the valve member and the inner surface ofthe bore 23 have been shown and described as being of spherical configura tion it will be understood that the invention is not limited to a spherical configurationl of such surfaces but that they can be conical,

ollipsoidal, paraboloidal, plate shaped, or any l other shape; the principal requirement being that these surfaceshave a contacting surface area extending transversely to the axis of roy tation of sulicientlextent to act as an efficient thrust bearing; For the purpose of rendering the self-adjustment of the valve and the bore of the `spindle'moreefliciently self-adjusting the lower portion of the cylindrical side wall of the valve is cut away as indicated by theireference character 90, so that the bearing surfaces of the valve andbore terminate approximately atthelower end of the spherical surfaceof the bore23. y

W'ith respect to the lubricating system it will be seen that with the present invention the lubricant contained in the compartment 13 automatically serves toy perform the following important functions: First, the carrying oil' of the heat of compression by conduction and circulation. Second, the silencing of the operation. Third, the lubrication and coolingof the main bearing 46 by directing onto and through it a copious stream of cooling lubricant under pressure. Fourth, acts as acushionfor end thrust upon the valve member 18. Fifth, provides pressure lubrication for said valves. Sixth, lubricates by contact the pistons A27 piston pin 3l and rollers 30. Seventh, provides a seal against gas or oil leakage about the periphery of the valve member 18. Eighth, provides a seal against leakage past the pistons, due to the fact that the cylinder bloc-k rotating at high speed acts as'a rotary pump for the lubricant in compartment 13 and sets up, by centrifugal force,

a pressure in the body of lubricant in excess of the pressure of compression, and Ninth, by contacting both with the exterior and interior vof the hollow pistonsr effectively cools them. As the compartment 13 is substantially filled with oil, a sufficient supply is provided so that refilling is unnecessary during a long period of operat-ion and furthermore no attention is necessary for lubricating or oiling any of the moving parts except to replenish the oil in the compartment 13 at comparatively long intervals. During the operation the pistons 27 are lubricated solely by the dipping contacting of the pistons with the oil at the outer end of the vpiston skirts, oil being. carried inwardly'toward the center of rotation, by the wiping action ofthe piston and capillarity, to a suflicient extent to insure complete lubrication of the entire length of the cylinders. The centrifugal force due to the rapid rotation of the cylinders makes the accumulation of any excess oil in the cylinderY heads impossible and therefore prevents the passage of any appreciable amount of oil into the air or other fluid being pumped bythe compressor. Proper lubrication of the rollers 30 and Y pins 31 is rendered more certain by'proportionmg the projecting ends of the pms 35 relatively to' the grooves 37 so as tol insure that as the .pistons reciprocate, said pin ends and said grooves'will function as small pistons and cylinders to produce a pulsating effect upon the lubricant inthe grooves and force it through the conduits 77, 781 and oil groove 7 9.

`While I have described the compartlnent 13 as being filled with oil it'pvvill be understood that the term oil has been used merely for convenience and not in a limiting sense; obviously any suitable liquid having lubricating qualities and the property of acting to conduct heat to the casing Walls may be used, Owing to the heat conduction from theipistons and cylinders to the Vcasing Walls by the lubricating Huid vand furthermore due to the' extra radiating surface provided by the conical inner ends of the cylinders and pistons, isothermal compression is more closely approached than VWith a compressor having fiat ended cylinders and pistons and consequently the eciency of the compressor is greatly increased. Y

Again While it is preferable to provide a sealed lubricant filled chamber in which the cylinders and pistons rotate, the use of such chamber is not absolutely essential as it will be obvious that therace 33 could kbe mounted upon a'iixed spider or other suitableskeleton support and air cooling of the cylinders employed. i i

During the rotation of the cylinders'cas'the pistons are moving outwardly on suction strokes the angular velocity of the piston rollers is increasing While on the compression stroke their velocity decreases, kineticenergy will therefore be stored up,V on. the suction stroke which increases the available power for the compression strokes. i f i As the suction strokes are performed While the pistons are moving outwardly and as the fluid being pumped is admitted approxi-v mately at the axis vof rotation, the rotation of the cylinders Will tend to set up a centrifugal force in the incoming Huid and consequently the. cylinders will be completely filled with iuidl on suction strokes thereby attaining maximum volumetric efficiency.

Whilel have disclosed the rotating cylinder block as being mounted upon a central spindle, it Willbe understoodthat the spindle and cylinder block could be made as a single casting. The constructionillustrated ioyvever is preferred because When an equal number of cylinders are provided, as shown, the boring of Vtivo diametrically opposite cylinders can be performed in one Operation.

It Will be noted that the valve 18 has its Yintake and discharge conduits both connecting with conduits in the stationary casing at the same end of the axis of rotation. This is a very important `advantage because it not only simplifies the construction considerably ,over one in which the intake and outlet conduits are at opposite ends of the axis of rotation but in addition renders it possible much more efficiently to seal the compressor against leakage about the valve can be sealed merely by pressure exerted towards that end of the casing through which the conduits of the valve connectwith the conduits of the casing, the pressure for insuringthe sealing of the contacting meeting` faces of the valve and the casing being provided by the spring 48. T he pressure of the spring 48 in addition to insuring the sealing of thefmeeting faces of the valve and casing, also serves in co-operation WithV the nested spherical surfaces of the spindle 22 and valve member to cause the latter to perform a steadying function some- AWhat similar to a lathe center even though the valve has a limited degree of free movementvwhich renders it self-adjusting. The sealing of the meeting faces of the valve and casing, as just described and the provision of the packing members 47 49 and 5() makes the compressorrivell adapted for-use with refrigerating linstallations or for pumping any dangerous gases. yMoreover, the danger of gas leakage vis reduced to a, minimum by operating the 4cylinders, and pistons in a fiuid tightchamber containing a body of'oil, the centrifugal forces due to the rotation of the cylinders maintaining the oil at the circumerential Wall of the compartment V13` so as to form an effective liquid seal, and at the same time said centrifugal forces tend to build up a pressure in the liquid, which being greater than the compression pressure, enables the liquid `also to prevent gas leale age outwardlybetween the pistons and cylinder walls.

In order to guard against the building up oi oil under pressure between the contacting bearing surfaces of the valve member 18 and the disc 19, and to guard against the leakage of oil between said surfaces and the passage of such oil into the delivery conduits 16, the upper face of the disc 19 is provided with a circular oil groove 91, arranged in spaced concentric relationship about the oil conduit 73. On that side of its circumference nearest to the conduits 16, the groove 91 communi-- cates with a second groove 92 which, as clearly shown in Fig. 12, surrounds the conduits 16 in spaced concentric relationship thereto. Means are provided for permitting the escape of oil entering the grooves 91, 92 into the interior of the compartment 13. Such means may consist of a groove such as the small groove 93, which communicates at the outer edge of the disc 19 with the compartment 13 and which at its inner end communicates with the `groove 92. The particular shape and location of what may be termedthe trans verse groove 93, obviously can be varied, for example, such groove could run substantially diametrically across the disc so as to communicate with both grooves 91 and 92.

1When the compressor is constructed in larger sizes for capacities beyond certain limits, or when smaller sizes are `subjected to such severe operating or service conditions that there will be tendency for it to heat up unduly, I contemplate the use of a radiating coil arranged exteriorly of the compartment 13, which coil will communicate at one end with the compartment 13 near the periplierythereof at a high pressure zone ofthe oil contents and which coil at its other end will communicate with said compartment pressure nearer to the axis of rotation at a low pressure zone. The oil within the compartment will therefore be circulated through the radiating coil to: be cooled in its passage therethrough and then returned tothe cornpartment 13.

While I have shown and described herein a `satisfactoryconsti-notional example ot my invention, it will be understood thatthe principles of the invention are not limited to the constructional detailsy illustrated, but that many changes, variations and modifications may be made'without departing from the spirit of lthe invention. For example, althrough the cylinders 24 and pistons 27have been shown asl extending radially from the axis of rotation, itwill be perfectly `obvious lthattheinventionisfnotlimited to a construction in which the longitudinal center linesLof the pistons and cylinders coincide with radii having'their centers at the axis of rotation. Therefore, the expression radially arranged cylinders or similar expressions contained inthe claims appended hereto is not to beconstrued as limiting the` invention to the specilic arrangement of the cylinders shown but is entitled to refer to` a` construction in which the cylinders are grouped about a central axis ofrotation whether radially to such axis, partly to radii extending from said axis or inclined to such fradii. i

Iclaim: v e i 1. Ain air compressor of the type wherein a plurali-ty of radially arranged cylinders each provided with a port at the inner end thereof is rotatable about a central valve memberprovided with inlet and discharge `ports with which the cylinder ports are brought into communication alternately by the rotation cliaracterizedby said valve member being provided `with an intake conduit and a discharge conduit terminating at one end respectively in alignment with said inlet and discharge ports, both of said conduits extending lengthwise of the axis of rotation and terminating at their other ends at the same end oi said axis of rotation.

2. An airlcompressor of the type wherein a plurality of radially arrangedcylinders each provided with a port at theinner end thereof isirotatable about a central valvememberpro vided Withyinlet and discharge portswith whichthe cylinder portsare brought into communication alternately by the rotation characterized by the provision of a stationary support for said valve member and cosoperating `interengaging devices von i said support and valve member to hold` said valve member normally against rotation but permitting a limitedfree degree of movementthereof.

3. A compressor as set forth in claim 2 in which the `rotating cylinders andvalve member are `provided `with cooperating bearing surfacesarranged in nested relationship and inclined to the axis ot rotation, and means for urging saidsurfaces towards each other with ayielding pressure whereby the `valve member will be self-adjusting? 4. In anaircompressor, a cylinder having a conical end atthe apex of which a port is provided, a piston slidably` mounted in said cylinder and having one end thereof of conical shape similar to that of said cylinder,

means to produce relative reciprocation betweensaid cylinder andpistomand a valve member adjacentto said port `and intersecting a portion of the conical end of said cylinder for controlling the alternate ingress and egress of .fluid to said cylinder, the conical shapesof the ends of said cylinderand piston and the intersection of said valve member rwith saidcylinder insuring theelimination `of dead air `pockets and reducing the `clearance volume to an irreducible minimum.

5r. An air compressor of the type wherein a plurality of radiallyfarranged cylinders each providedwith a port at the innerend thereof is rotatable about a vcentral valve member provided with'inlet and discharge `ports with which the cylinder ports are i hole terminating'at the center of said bearing surfaces, means to force a lubricant under pressure through said oil hole and 'an oil groove encircling said oil hole, whereby an area of lubricant under pressure is provided adjacent to the center of said bearing surfaces. j i I 6. A compressor as set forth'in claim 5 in which a radial oil channel connects with said oil groove and terminates outside of said bearing surfaces for permitting escape'of excess oil.

7 A compressor as setjforth in claimf in which said oil groove is provided inthe central bearing. of 4the rotating cylinder 'structure whereby excess'of oil is forced lintosaid oil groove by centrifugal force.

.8. A compressor comprising a central rotatable driving shaft, and a bearing therefor, a plurality of radial cylinderssecured to said shaft, a fluid tight casing in whichv said cylinders are mounted, said casing containing a liquid having high heat conducting and lubricating properties, an oil conduit leading from said casing in the high pressure region of said liquid produced by centrifugal forces, said oil conduit terminating at'said bearing and a return connection from said bearing to said casing and terminating in a low pressure region of the latter. i i Y 9. A compressor comprising a central rotatable driving shaft, a plurality of radially extending cylinders secured'to said shaft, a

.fluid tight casing in which said cylinders-ro`- tate, a valve member located at the inner ends of said cylinders, said 'cylinders and valve l' member being provided with co-operating bearing surfaces, an oil conduit leading from a high pressure region of said casing to said bearing surfaces and a return connection from said surfaces to a low pressure region of said-casing.

10. A compressoras set forth in claim 8 lin whicha valve member is located at the inner end of said cylinders,` said cylinders and valve members being provided withvc'ooperating bearing surfaces,"an oil'c'onduit leads from the highpressure region of said *casing to said bearing surfaces, anda "return connection extends-from saidI surfaces .to a

flow pressure region'of said casing.

" 11. A compressor as set forth in claim 8 in which a valve member is located at the inner end of said cylinders, said cylinders and v'alvemembers being provided with cooper ating bearing surfaces, an oil conduit leads Vfrom the high pressure reg-ion of said casing to said bearing surfaces, and a return conneo tion extends from said surfaces to a low pressureregion of said casing, and means are provided for controlling the rate of flowlof lubricating liquid through said last named conduit.l Y v 12. A compressor comprising a'pair of cas- Vcasing members. i Y

'13. A compressor comprising ar plurality of cylinders equally spaced about a'common axis of rotation and extending radially therefrom, a' piston mounted for reciprocation in eachV of said cylinders, a two-part fluid tight casing in whichsaid cylinders areinounted, and a circular race fixed within said casing at the meeting joint of said twopart casing land eccentrically of said axis, and means car ried by said pistons for engagement with said race, said race serving as a gasket for said meeting joint and also to cause said pistons to perform'their compression strokes.

14. compressor comprising a Vplurality iY fof cylinders, rotatable about a common axis of rotation, and extending radially thereto, aI piston slidabl'y mounted in each cylinder, a

Acircula-r race secured to a fixed support eccentrically of Vsaid axis, and anti-friction -ineans carriedby saidV pistons for engagement with saidvrace, said race serving to cause said pistons to move inwardly of said cylinders to 'perforinrtheir compression strokes and said pistons being moved outwardly towards said race solely bythe centrifugal forces 'due to the rotation of said cylinders.

15.A compressor as set forth in .claim 14 'in which the anti-friction means and said race are 'provided with interengaging parts for preventing rotation of-said pistons about 16. A compressor comprising a plurality of pistons rotatable about a common axis in a fluid tightilubricant filled casing,a circular `Sti fri

rac-e secured to said casing eccentricallybf said axis, a piston mounted for reciprocation in each cylinder and having a roller for engagement with said race, a pin car1'1ed by each piston upon which its respective roller is rotatably mounted each said cylinder and piston being provided one with a longitudinally extending channel and the other with a `ju'ojection protruding into said channel, and each said pin having an oil conduit communicating at one end with said channel and terminating at the other end at the bearing surfaces of said pin and roller, whereby, during reciprocation of said piston, lubricant within said channel will be impelled by said projection into and through said oil conduit to said bearing surfaces.

17. A compressor as set forth in claim 13 1n which said race has circular outer and inner faces eccentric to each other, the outer face being seated wit-hin a circular support eccentric to the axis of rotation of said cylinders whereby rotary adjustment of said race within said support will vary the effective eccentricity of said race relatively to the axis of rotation of said cylinders.

18. A compressor as set forth in claim 13 in which said race has circular outer and inner faces eccentric to each other, the outer face being seated within a circular support eccentric to the axis of rotation of said cylinders whereby rotary adjustment of said race within said support will vary the effective eccentricity of said race relatively to the axis of rotation of said cylinders and means for producing rotary adjustment of said race.

15). In a compressor, a cylinder having a conical head and a port at the apex thereof, a valve having a ported spherical surface located at said apex and a piston slidably mounted in said cylinder and having a conical j head that fits exactly the conical head of said cylinder, and the conical head of said piston being truncated by the intersection 'of a sphere of the same diameter as the spherical surface of said valve whereby all valve pockets are eliminated and clearance space is reduced to an irreducible minimum.

20. In a. compressor, a driving shaft, a driven shaft, a coupling connecting said shafts in torque transmitting relationship and preventing relative axial movement between said shafts, a casing having a bearing concentrically surrounding said driven shaft in spaced relationship thereto, said driven shaft having a laterally projecting flange or shoulder' defining with said bearing a pocket, an antifriction bearing member in said pocket, a spring bearing against said bearing member to hold it against said flange and a plurality of members, including a packing gasket, for retaining said spring in position and defining' a stuffing box for said casing.

21. An air compressor of the type Wherein a plurality of rotating cylinders each havcyIinderS, `chaaulacterized b and pistons berno'` mounte 1 within a sealed berend means are providediffor rotating said lubricant containing chamber and said valve member being mounted for limited self-adjusting` movement uponA `a ibearing plate, a. lubricating conduit `extending through said valve memberand bea-ring plate `and communicating with said chamber near the outer wallsthereoacircular oil groove surrounding said conduit and a second oil groove extending from said circular groove and communicating with said Vcompartment near the center thereof. j

22. In a compressor, a plurality of cylinders and pistons rotatable ina closed lubricant containing chamber, a pair of spaced axially aligned bearings upon which said cylinders rotate, conduits leading from said chamber adjacent to the outer walls thereof to said bearings, connections leading from said bearings to said compartment adjacent to the center; thereof, a mass of resilient porous material extending across one of said conduits and means to adjustably compress said mass of material thereby to vary the effective ,porosity thereof and control the rate of flow of the lubricantthrough said one conduit.

23. A compressor comprising a fluid tight chamber, a plurality of cylinders each having a piston mounted for reciprocation therein enclosed within said chamber, inlet and discharge conduits adapted to be placed in communication with said cylinders passing throughr said chamber but normally out of communication therewith, said chamber being provided with but a single aperture, driving means passing through said aperture and a fluid tight stuing box surrounding said driving means adjacent to said aperture whereby if leakage of the fluid pumped by said compressor should occur from said cylinders or conduits escape thereof from said chamber will be prevented.

24. A compressor comprising a plurality of cylinders rotatable about a common axis, each of said cylinders having a piston slidably mounted therein, means for producing relative reciprocation between said cylinders and pistons, including a central driving shaft upon which said cylinders are mounted, a casing enclosing said cylinders and pistons having an extended exposed, radiating surface, and means for drawing a current of cooling air across said surface comprising a fan mounted on said driving shaft and deflecting means for causing the air currents produced by the rotation of said fan to sweep i across substantially the entire area of said radiating surface.

25. A compressor, a set forth in claim 24, in which an electric motor is employed as a primemover and is connected with the central? `said `cylinders Asrs Y driving shaft, anddeflectinglmeans is prol vided with a central aperture surroundlng said driving shaft,vsaid fan andV deflecting means' causing the cooling current of air lto be orced'through the electric. motor and Y drawn across the radiating surface of the compressor,v whereby the air propelled `by Y lsaid fan produces a cooling effect upon both the motor and compressor. c

' vIn testimony whereof I have hereunto set A my hand. l

, -f WALTER H. RUDOLPH. 

